Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932328AbcDDPgo (ORCPT ); Mon, 4 Apr 2016 11:36:44 -0400 Received: from mga09.intel.com ([134.134.136.24]:29690 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752203AbcDDPgn (ORCPT ); Mon, 4 Apr 2016 11:36:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,441,1455004800"; d="scan'208";a="777782660" Subject: Re: [PATCH v5 3/9] x86/head: Move early exception panic code into early_fixup_exception To: Andy Lutomirski , Jan Kara References: <4085070316fc3ab29538d3fcfe282648d1d4ee2e.1459605520.git.luto@kernel.org> <20160402183919.GA2538@pd.tnic> <20160402204752.GC2538@pd.tnic> <20160404115206.GG8372@quack.suse.cz> Cc: Paolo Bonzini , xen-devel , Borislav Petkov , X86 ML , Andrew Morton , Petr Mladek , KVM list , "linux-kernel@vger.kernel.org" , Linus Torvalds , Peter Zijlstra From: Arjan van de Ven Message-ID: <57028A03.3000902@linux.intel.com> Date: Mon, 4 Apr 2016 08:36:35 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 563 Lines: 14 On 4/4/2016 8:32 AM, Andy Lutomirski wrote: > > Adding locking would be easy enough, wouldn't it? > > But do any platforms really boot a second CPU before switching to real > printk? Given that I see all the smpboot stuff in dmesg, I guess real > printk happens first. I admit I haven't actually checked. adding locking also makes things more fragile in terms of getting the last thing out before you go down in flaming death.... until it's a proven problem, this early, get the message out at all is more important than getting it out perfectly, sometimes.